The present invention relates to a cable and yarn double-twisting spindle having a pneumatic yarn threader.
A so-called combination spindle unit, which can be operated in correspondence with the type of yarn as either a double-twisting spindle by which the yarn drawn from the top of one or several yarn feed packages is guided through the hollow spindle axial portion, thereafter radially through a yarn guide channel traveling about a rotation plate with its associated balloon limiter to a central guide eyelet, and subsequently wound as a double-twisted yarn, or as a cable spindle in which the yarn drawn from the top of a feed package, preferably a filament yarn, is guided in the same manner as in the yarn twisting process and is united in the region of the radially traveling yarn channel with a yarn component delivered from below via the spindle shaft channel.
From DE 41 03 286 C2, it is known to provide pressurized air through an injector jet of a twist spindle which is disposed centrally in the rotation plate and which communicates radially with the yarn guide channel such that the supply of pressurized air through the injector jet into the spindle hollow axial portion produces a suction effect operable to thread a yarn, disposed at the upper end of the spindle hollow axial portion, through the spindle hollow axial portion and the yarn guide channel.
A cable spindle described in DE 43 09 474 C1 is provided with a regulating or tension compensating element for regulating or tension compensating, respectively, the yarns of various tensions to be cabled, this element having yarn guide channels and yarn guide rollers comprised in a housing arrangement. To effect threading up of an individual yarn through the housing enclosure, a pressurized air conduit is communicated with each yarn guide channel such that a suction flow is produced in the first section of such yarn guide channels while a pressurized air flow is produced in the next following section of the channels.
The present invention provides a solution to the challenge of providing a spindle by which such a pneumatic threading up of the respective yarn is possible in both the operation of the spindle as a yarn double-twisting spindle and the operation of the spindle as a cable spindle.
The solution to this challenge is delineated by the features of the spindle as set forth in the claims herein.
In contrast to the yarn twisting spindle described in DE 41 03 286 C2 whose spindle shaft bore is configured solely as a pressurized air supply conduit for the injector jet, the inventive spindle of the present invention is characterized in that the pressurized air path to the injector jet is configured such that additionally in the spindle shaft bore a suction flow is produced for threading up a yarn disposed at the spindle shaft bore and drawn, for example, from a feed package on a frame.
In accordance with one embodiment of the present invention, the spindle shaft is provided with an axial yarn guide channel communicating with the interior of the yarn guide channel of the rotating plate, this axial yarn guide channel being encircled by a ring channel terminating at a spacing below the yarn guide channel of the rotating plate operable to guide pressurized air therethrough and on whose upper end eccentrically oriented channel segments leading to the injector jets are communicated.
In accordance with another embodiment of the present invention, it is provided that the pressurized air is guided not axially through the spindle shaft but is guided, instead, radially through the support hub in that the hub is provided with a lateral pressurized air throughbore which communicates with a ring space surrounding the spindle shaft which itself is communicated with the injector jet via a substantially axially oriented pressurized air channel segment.